PushButton library converts & simulates the smartphone as a real Hardware push button so that you can control physical objects surrounding you.
Adding #define CUSTOM_SETTINGS along with #define INCLUDE_PUSH_BUTTON_SHIELD is a key that will let you unlock the Push Button shield only amongst all shields and prevent 1Sheeld library from eating your memory specially for UNO board.
Checks if the button is pressed or not.
A yes “1” or no “0”.
bool value = PushButton.isPressed();
Sets a certain individual function written by the user in the sketch to be called and runs its functionality each time the push button is pressed.
&userFunctionName: takes the physical address of the userFunction in the memory and jump to it once called to execute it’s functionality.
/* myFunction exists under the loop function. */
/* This function will be invoked each time a the button is pressed. */
void myFunction (byte isButtonPressed)
/*Turn on a LED if button pressed. */